PS. Good choice of carbon/Kevlar. that will give you good impact resistance and strength.

PSS Have you considered that there may need to be a certain amount of flex in the helmet to absorb the impact? Super stiff may transfer the force rather than absorb it?

It's got channels at the back which makes it extremely difficult to make it perfect. The inside is fuuurfect. Which makes me think to reverse the mold to a female one. Easy peasy.
For a first run I am more than happy. A few epoxy coats and won't be visible:)

There is a flex, no probs with that. There will be more of it when cut to a final shape with more open forehead, like ie. Gath. The idea is a skin helmet, tho. With the ears protection as well (a new mold).